This attribute indicates the direction in which V.42bis is active,
negotiated at link setup by the data link protocol through Exchange
Identification (XID) negotiation of parameter P0 (compression
direction). The value used for XID negotiations can be provisioned
via TdmaCs/* V42bis. This attribute has one of the following
values:
noCompression: No data compression.
compInitrResp: The data sent by the IWF to the other entity is
compressed.
compRespInitr: The data received by the IWF from the other entity
is compressed.
compBoth: compression in both directions.